Having pledged to stick to Osborne's spending limits, more generous benefits for some will need to be paid for by cuts or tax rises elsewhere.

Shadow work and pensions secretary Liam Byrne argues that "social security should offer more for those that chipped in most". Photograph: Getty Images.

In a speech later today, Liam Byrne will rightly highlight[3] what he calls "the scandal of the silver scrapheap". Nearly half of all unemployed people in their 50s have been out of work for longer than a year and the over 50s now spend longer on Jobseeker's Allowance (JSA) than any other age group, an average of 32 weeks.

As Byrne will argue, the social security system currently fails such people. Having paid an average of £100,000 in National Insurance, they find they are entitled to just £71.70 a week in contributory JSA and will lose all support after six months if they have savings of £16,000 or a partner who works more than 24 hours a week. While the welfare system is often accused of offering "something for nothing", for these people it's more like nothing for something. "It makes you wonder why we bothered paying in all those years" Byrne quotes one man as saying, "they don’t bother to look at our skills. They tell us to apply for anything. It’s just banging square pegs into round holes". With this in mind, the shadow work and pensions secretary will reaffirm Labour's commitment to examine a higher rate of JSA for those who have contributed more. He writes:

I think social security should offer more for those that chipped in most either caring or paying in National Insurance. Our most experienced workers and carers have earned an extra hand. We should make sure there something better for when they need it. That’s why we’re looking at just how we put the something for something bargain at the heart of social security reform, starting with a new deal for the over 50s.

In addition, he suggests that the UK could follow countries like Japan, Canada and the US in developing specialised support services for older workers, such as training grants. In the long-run, he argues, such measures would pay in part or in full for themselves, nothing that "if we raised the employment rate amongst our over 50s to the level enjoyed by Japan, they’d be 438,000 more people in work, and £3 billion in extra tax flowing into the Treasury".

But what Byrne doesn't say is how more generous benefits for older people will be paid for in the short-term. Having pledged to stick to George Osborne's 2015-16 current spending limits, any new spending promises will have to be funded by cuts or higher taxes elsewhere. In his recent speech on welfare, Ed Miliband suggested that the qualifying period for contributory JSA could be extended from two years to five years. In other words, the young will pay for the old. But not only is it questionable whether it's right to reduce support for the young at a time when so many suffer spells of unemployment (or to create a benefits system that favours the fortunate), it's also unclear how much money this reform would save. Young people are far less likely to have savings of £16,000 or more and/or a partner in work, meaning many will continue to qualify for means-tested JSA. If Labour wants to build a social security system that genuinely offers what Byrne calls "a new deal" for the over-50s, it will need to spend a significant amount. Until it makes it clear who will pick up the bill, the Tories will be able to charge Labour with promising more of the unfunded spending that "got us into this mess".